package kr.co.iniline.j2glsl.example;

import static org.lwjgl.opengl.GL11.*;

import java.nio.FloatBuffer;

import org.lwjgl.BufferUtils;

/**
 * Reference by : https://bitbucket.org/chuck/lwjgl-sandbox, src/main/java/sandbox/util/Teapot.java
 */
public class Teapot {

	/**
	 * Renders the teapot as a solid shape of the specified size. The teapot is
	 * created in a way that replicates the C GLUT implementation.
	 * 
	 * @param scale
	 *            the factor by which to scale the teapot
	 */
	public static void glutSolidTeapot(double scale) {
		glutSolidTeapot(scale, true);
	}

	/**
	 * Renders the teapot as a solid shape of the specified size. The teapot can
	 * either be created in a way that is backward-compatible with the standard
	 * C glut library (i.e. broken), or in a more pleasing way (i.e. with
	 * surfaces whose front-faces point outwards and standing on the z=0 plane,
	 * instead of the y=-1 plane). Both surface normals and texture coordinates
	 * for the teapot are generated. The teapot is generated with OpenGL
	 * evaluators.
	 * 
	 * @param scale
	 *            the factor by which to scale the teapot
	 * @param cStyle
	 *            whether to create the teapot in exactly the same way as in the
	 *            C implementation of GLUT
	 */
	public static void glutSolidTeapot(double scale, boolean cStyle) {
		teapot(14, scale, GL_FILL, cStyle);
	}

	/**
	 * Renders the teapot as a wireframe shape of the specified size. The teapot
	 * is created in a way that replicates the C GLUT implementation.
	 * 
	 * @param scale
	 *            the factor by which to scale the teapot
	 */
	public static void glutWireTeapot(double scale) {
		glutWireTeapot(scale, true);
	}

	/**
	 * Renders the teapot as a wireframe shape of the specified size. The teapot
	 * can either be created in a way that is backward-compatible with the
	 * standard C glut library (i.e. broken), or in a more pleasing way (i.e.
	 * with surfaces whose front-faces point outwards and standing on the z=0
	 * plane, instead of the y=-1 plane). Both surface normals and texture
	 * coordinates for the teapot are generated. The teapot is generated with
	 * OpenGL evaluators.
	 * 
	 * @param scale
	 *            the factor by which to scale the teapot
	 * @param cStyle
	 *            whether to create the teapot in exactly the same way as in the
	 *            C implementation of GLUT
	 */
	public static void glutWireTeapot(double scale, boolean cStyle) {
		teapot(10, scale, GL_LINE, cStyle);
	}

	// Teapot implementation (a modified port of glut_teapot.c)
	//
	// Rim, body, lid, and bottom data must be reflected in x and
	// y; handle and spout data across the y axis only.
	private static final int[][] teapotPatchData = {
			/* rim */
			{ 102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
			/* body */
			{ 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 },
			{ 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 },
			/* lid */
			{ 96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0, 1, 2, 3, },
			{ 0, 1, 2, 3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
					116, 117 },
			/* bottom */
			{ 118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120, 40,
					39, 38, 37 },
			/* handle */
			{ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56 },
			{ 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 28, 65, 66, 67 },
			/* spout */
			{ 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83 },
			{ 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95 } };
	public static final float[][] teapotCPData = { { 0.2f, 0f, 2.7f },
			{ 0.2f, -0.112f, 2.7f }, { 0.112f, -0.2f, 2.7f },
			{ 0f, -0.2f, 2.7f }, { 1.3375f, 0f, 2.53125f },
			{ 1.3375f, -0.749f, 2.53125f }, { 0.749f, -1.3375f, 2.53125f },
			{ 0f, -1.3375f, 2.53125f }, { 1.4375f, 0f, 2.53125f },
			{ 1.4375f, -0.805f, 2.53125f }, { 0.805f, -1.4375f, 2.53125f },
			{ 0f, -1.4375f, 2.53125f }, { 1.5f, 0f, 2.4f },
			{ 1.5f, -0.84f, 2.4f }, { 0.84f, -1.5f, 2.4f },
			{ 0f, -1.5f, 2.4f }, { 1.75f, 0f, 1.875f },
			{ 1.75f, -0.98f, 1.875f }, { 0.98f, -1.75f, 1.875f },
			{ 0f, -1.75f, 1.875f }, { 2f, 0f, 1.35f }, { 2f, -1.12f, 1.35f },
			{ 1.12f, -2f, 1.35f }, { 0f, -2f, 1.35f }, { 2f, 0f, 0.9f },
			{ 2f, -1.12f, 0.9f }, { 1.12f, -2f, 0.9f }, { 0f, -2f, 0.9f },
			{ -2f, 0f, 0.9f }, { 2f, 0f, 0.45f }, { 2f, -1.12f, 0.45f },
			{ 1.12f, -2f, 0.45f }, { 0f, -2f, 0.45f }, { 1.5f, 0f, 0.225f },
			{ 1.5f, -0.84f, 0.225f }, { 0.84f, -1.5f, 0.225f },
			{ 0f, -1.5f, 0.225f }, { 1.5f, 0f, 0.15f },
			{ 1.5f, -0.84f, 0.15f }, { 0.84f, -1.5f, 0.15f },
			{ 0f, -1.5f, 0.15f }, { -1.6f, 0f, 2.025f },
			{ -1.6f, -0.3f, 2.025f }, { -1.5f, -0.3f, 2.25f },
			{ -1.5f, 0f, 2.25f }, { -2.3f, 0f, 2.025f },
			{ -2.3f, -0.3f, 2.025f }, { -2.5f, -0.3f, 2.25f },
			{ -2.5f, 0f, 2.25f }, { -2.7f, 0f, 2.025f },
			{ -2.7f, -0.3f, 2.025f }, { -3f, -0.3f, 2.25f },
			{ -3f, 0f, 2.25f }, { -2.7f, 0f, 1.8f }, { -2.7f, -0.3f, 1.8f },
			{ -3f, -0.3f, 1.8f }, { -3f, 0f, 1.8f }, { -2.7f, 0f, 1.575f },
			{ -2.7f, -0.3f, 1.575f }, { -3f, -0.3f, 1.35f },
			{ -3f, 0f, 1.35f }, { -2.5f, 0f, 1.125f },
			{ -2.5f, -0.3f, 1.125f }, { -2.65f, -0.3f, 0.9375f },
			{ -2.65f, 0f, 0.9375f }, { -2f, -0.3f, 0.9f },
			{ -1.9f, -0.3f, 0.6f }, { -1.9f, 0f, 0.6f }, { 1.7f, 0f, 1.425f },
			{ 1.7f, -0.66f, 1.425f }, { 1.7f, -0.66f, 0.6f },
			{ 1.7f, 0f, 0.6f }, { 2.6f, 0f, 1.425f }, { 2.6f, -0.66f, 1.425f },
			{ 3.1f, -0.66f, 0.825f }, { 3.1f, 0f, 0.825f }, { 2.3f, 0f, 2.1f },
			{ 2.3f, -0.25f, 2.1f }, { 2.4f, -0.25f, 2.025f },
			{ 2.4f, 0f, 2.025f }, { 2.7f, 0f, 2.4f }, { 2.7f, -0.25f, 2.4f },
			{ 3.3f, -0.25f, 2.4f }, { 3.3f, 0f, 2.4f }, { 2.8f, 0f, 2.475f },
			{ 2.8f, -0.25f, 2.475f }, { 3.525f, -0.25f, 2.49375f },
			{ 3.525f, 0f, 2.49375f }, { 2.9f, 0f, 2.475f },
			{ 2.9f, -0.15f, 2.475f }, { 3.45f, -0.15f, 2.5125f },
			{ 3.45f, 0f, 2.5125f }, { 2.8f, 0f, 2.4f }, { 2.8f, -0.15f, 2.4f },
			{ 3.2f, -0.15f, 2.4f }, { 3.2f, 0f, 2.4f }, { 0f, 0f, 3.15f },
			{ 0.8f, 0f, 3.15f }, { 0.8f, -0.45f, 3.15f },
			{ 0.45f, -0.8f, 3.15f }, { 0f, -0.8f, 3.15f }, { 0f, 0f, 2.85f },
			{ 1.4f, 0f, 2.4f }, { 1.4f, -0.784f, 2.4f },
			{ 0.784f, -1.4f, 2.4f }, { 0f, -1.4f, 2.4f }, { 0.4f, 0f, 2.55f },
			{ 0.4f, -0.224f, 2.55f }, { 0.224f, -0.4f, 2.55f },
			{ 0f, -0.4f, 2.55f }, { 1.3f, 0f, 2.55f },
			{ 1.3f, -0.728f, 2.55f }, { 0.728f, -1.3f, 2.55f },
			{ 0f, -1.3f, 2.55f }, { 1.3f, 0f, 2.4f }, { 1.3f, -0.728f, 2.4f },
			{ 0.728f, -1.3f, 2.4f }, { 0f, -1.3f, 2.4f }, { 0f, 0f, 0f },
			{ 1.425f, -0.798f, 0f }, { 1.5f, 0f, 0.075f }, { 1.425f, 0f, 0f },
			{ 0.798f, -1.425f, 0f }, { 0f, -1.5f, 0.075f },
			{ 0f, -1.425f, 0f }, { 1.5f, -0.84f, 0.075f },
			{ 0.84f, -1.5f, 0.075f } };
	// Since glMap2f expects a packed array of floats, we must convert
	// from a 3-dimensional array to a 1-dimensional array
	private static final float[] teapotTex = { 0, 0, 1, 0, 0, 1, 1, 1 };

	public static FloatBuffer toBuffer(float[] src) {
		FloatBuffer buffer = BufferUtils.createFloatBuffer(src.length);
		buffer.put(src);
		buffer.rewind();
		return buffer;
	}

	private static void teapot(int grid, double scale, int type,
			boolean backCompatible) {
		// As mentioned above, glMap2f expects a packed array of floats
		float[] p = new float[4 * 4 * 3];
		float[] q = new float[4 * 4 * 3];
		float[] r = new float[4 * 4 * 3];
		float[] s = new float[4 * 4 * 3];
		int i, j, k, l;

		glPushAttrib(GL_ENABLE_BIT | GL_EVAL_BIT | GL_POLYGON_BIT);
		glEnable(GL_AUTO_NORMAL);
		glEnable(GL_MAP2_VERTEX_3);
		glEnable(GL_MAP2_TEXTURE_COORD_2);
		glPushMatrix();
		if (!backCompatible) {
			// The time has come to have the teapot no longer be inside out
			glFrontFace(GL_CW);
			glScaled(0.5 * scale, 0.5 * scale, 0.5 * scale);
		} else {
			// We want the teapot in it's backward compatible position and
			// orientation
			glRotatef(270.0f, 1, 0, 0);
			glScalef((float) (0.5 * scale), (float) (0.5 * scale),
					(float) (0.5 * scale));
			glTranslatef(0.0f, 0.0f, -1.5f);
		}
		for (i = 0; i < 10; i++) {
			for (j = 0; j < 4; j++) {
				for (k = 0; k < 4; k++) {
					for (l = 0; l < 3; l++) {
						p[(j * 4 + k) * 3 + l] = teapotCPData[teapotPatchData[i][j
								* 4 + k]][l];
						q[(j * 4 + k) * 3 + l] = teapotCPData[teapotPatchData[i][j
								* 4 + (3 - k)]][l];
						if (l == 1)
							q[(j * 4 + k) * 3 + l] *= -1.0;
						if (i < 6) {
							r[(j * 4 + k) * 3 + l] = teapotCPData[teapotPatchData[i][j
									* 4 + (3 - k)]][l];
							if (l == 0)
								r[(j * 4 + k) * 3 + l] *= -1.0;
							s[(j * 4 + k) * 3 + l] = teapotCPData[teapotPatchData[i][j
									* 4 + k]][l];
							if (l == 0)
								s[(j * 4 + k) * 3 + l] *= -1.0;
							if (l == 1)
								s[(j * 4 + k) * 3 + l] *= -1.0;
						}
					}
				}
			}

			// glMap2f(int target, float u1, float u2, int ustride, int uorder,
			// float v1, float v2, int vstride, int vorder, java.nio.FloatBuffer
			// points)
			// glMap2f(int target, float u1, float u2, int ustride, int uorder,
			// float v1, float v2, int vstride, int vorder, const GLfloat
			// *points)
			// glMap2f(GLenum target, GLfloat u1, GLfloat u2, GLint ustride,
			// GLint uorder, GLfloat v1, GLfloat v2, GLint vstride, GLint
			// vorder, const GLfloat *points)

			glMap2f(GL_MAP2_TEXTURE_COORD_2, 0.0f, 1.0f, 2, 2, 0.0f, 1.0f, 4,
					2, toBuffer(teapotTex));
			glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, toBuffer(p));
			glMapGrid2f(grid, 0.0f, 1.0f, grid, 0.0f, 1.0f);
			evaluateTeapotMesh(grid, type, i, !backCompatible);
			glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, toBuffer(q));
			evaluateTeapotMesh(grid, type, i, !backCompatible);
			if (i < 6) {
				glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, toBuffer(r));
				evaluateTeapotMesh(grid, type, i, !backCompatible);
				glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, toBuffer(s));
				evaluateTeapotMesh(grid, type, i, !backCompatible);
			}
			// glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 2, 2, 0, 1, 4, 2,
			// teapotTex, 0);
			// glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, p, 0);
			// glMapGrid2f(grid, 0.0f, 1.0f, grid, 0.0f, 1.0f);
			// evaluateTeapotMesh(grid, type, i, !backCompatible);
			// glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, q, 0);
			// evaluateTeapotMesh(grid, type, i, !backCompatible);
			// if (i < 6) {
			// glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, r, 0);
			// evaluateTeapotMesh(grid, type, i, !backCompatible);
			// glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, s, 0);
			// evaluateTeapotMesh(grid, type, i, !backCompatible);
			// }
		}
		glPopMatrix();
		glPopAttrib();
	}

	private static void evaluateTeapotMesh(int grid, int type, int partNum,
			boolean repairSingularities) {
		if (repairSingularities && (partNum == 5 || partNum == 3)) {
			// Instead of using evaluators that give bad results at
			// singularities,
			// evaluate by hand
			glPolygonMode(GL_FRONT_AND_BACK, type);
			for (int nv = 0; nv < grid; nv++) {
				if (nv == 0) {
					// Draw a small triangle-fan to fill the hole
					glDisable(GL_AUTO_NORMAL);
					glNormal3f(0, 0, partNum == 3 ? 1 : -1);
					glBegin(GL_TRIANGLE_FAN);
					{
						glEvalCoord2f(0, 0);
						// Note that we draw in clock-wise order to match the
						// evaluator
						// method
						for (int nu = 0; nu <= grid; nu++) {
							glEvalCoord2f(nu / (float) grid, (1f / grid)
									/ (float) grid);
						}
					}
					glEnd();
					glEnable(GL_AUTO_NORMAL);
				}
				// Draw the rest of the piece as an evaluated quad-strip
				glBegin(GL_QUAD_STRIP);
				{
					// Note that we draw in clock-wise order to match the
					// evaluator method
					for (int nu = grid; nu >= 0; nu--) {
						glEvalCoord2f(nu / (float) grid, (nv + 1)
								/ (float) grid);
						glEvalCoord2f(nu / (float) grid,
								Math.max(nv, 1f / grid) / (float) grid);
					}
				}
				glEnd();
			}
		} else {
			glEvalMesh2(type, 0, grid, 0, grid);
		}
	}

}